I have had it, bilat, for 2 yrs. Just had surgery on my right foot. Even if it doesn't give me 100% cure, its got to be an improvement. I would recommend that she see a dr. who performs the endoscopic plantar fasciotomy. I saw a dr. yesterday who said he recommends surgery after 6 months of no results from conservative txs. This is very liberal; most drs. require you to suffer much longer.
I went to a very good expert in Houston. I can give you all the info. if you are interested. He has a web page a www.footspecialist.com. Take a look.
I am making a good recovery from surg. 2 weeks ago. I am still using crutches, but most folks progress faster, I'm told. There's a big debate about the endoscopic vs. the traditional surgery, so you will want to do some research into that. I'm sold on the endoscope; hardly any pain and a quick recovery.
Best of luck to your mom and you.